CLIN CHEM: Question 3

What is 5-HIAA?

Also Known As

HIAA

Serotonin Metabolite

Formal Name

5-hydroxyindoleacetic Acid

5-hydroxyindoleacetic acid (5-HIAA) is the primary metabolite of serotonin, a chemical substance (neurotransmitter) that transmits messages between nerve cells, constrict blood vessels, participates in the wake-sleep cycle, and affects mood. After it is used by the body, serotonin is broken down in the liver, and its metabolites, including 5-HIAA, are excreted in the urine.

Ordinarily, only small varying amounts of 5-HIAA are present in the urine. Large quantities of serotonin and 5-HIAA may be produced, however, by some carcinoid tumors.  Carcinoid tumors are slow-growing noncancerous or cancerous neuroendocrine masses that can form in the GI tract, especially in the appendix, and in the lungs.

source: labtestsonline.org

CLIN CHEM: Question 2

ANTI-SMITH ABs(Anti-Sm)  are very specific markers for ______:

a. Scleroderma
b. Sjogren's Syndrome
c. Systemic Lupus Erythematosus (SLE)
d. (MCTD) Mixed Connective Tissue Disease ANSWER:  c. SLE

CLIN CHEM: Question 1

APO A1  is the major protein component of ______:

a. HDL b. LDL c. VLDL d. Chylomicrons

ANS:  a. HDL

NOTES: Deficiency of apo A1 is associated with HDL deficiencies, including Tangier disease and systemic non-neuropathic amyloidosis. Apo A1 may have a role in protection against Alzheimer's disease. SOURCE: patient.info/doctor/apolipoproteins